Art of making yarn guides for knitting machines



1942- A. WEISBECKER ,30

ART OF MAKING YARN GUIDES FOR KNITTING MACHINES 7 Original Filed March 23, 1939 2 Sheets$heet 1 12 I 3nnentor mwm 715 6 1942. A. 1.. WEISBECKER 2,301,652

ART OF MAKING YARN GUIDES FOR KNITTING MACHINES Original Filed March 23, 1959 2 Sheets-Sheet 2 i fin'oentor 18 womwmm (Ittomeg Patented Nov. 10, 1942 UNITED STATES PATENT OFFICIE ART OF MAKING YARN GUIDES FOR KNITTING MACHINES August L. Wcisbecker, North Glcnside, Pa., assignor to Hosiery Patents Incorporated, Lansdale, Pa., a corporation of Pennsylvania 6 Claims.

The present invention relates to a method of making yarn guides for use in yarn carriers of knitting machines. The yarn guides of this invention are especially useful in straight knitting machines for producing full-fashioned hosiery, although it will be readily appreciated from an understanding of this disclosure that the present invention is applicable to the yarn feeding means of other types of knitting machines. This application is a division of my copending application Serial No. 263,737, filed March 23, 1939, now Patent No. 2,218,977, dated October 22, 1940.

Prior forms of yarn carriers adapted for use in full-fashioned hosiery straight knitting machines are disclosed in the following patents issued to Frank G. Weisbe-cker, 2,026,514, dated December 31, 1935; 2,014,341, dated September 10, 1935; and 2,101,801, dated December '7, 1937. These patents may be referred to for an explanation of the operation of a yarn carrier in a straight knitting machine and for an explanation of some of the advantages of yielding yarn carrier constructions and flexible yarn guide tubes for yarn carriers.

An object of this invention is to provide a novel method for making yarn guide tubes.

Another object is to provide a novel method for making yarn carrier guide tubes which method is relatively simple and inexpensive and which method may be followed to produce a highly satisfactory article with a minimum of work being involved in its manufacture.

Other objects and advantages Will appear from the following description, the appended claims,

and the accompanying drawings, which illustrate I embodiments of this invention.

In the accompanying'drawings, Figure 1 shows a yarn carrier construction, this view showing a yarn guide tube and an end of a yarn carrier member to which the yarn guide tube is attached.

Figure 2 is a View similar to Figure 1 and shows another yarn carrier construction.

Figure 3 is an enlarged View, partly in elevation and partly in cross section, of the yarn guide tube shown in Figure 1.

Figure 4 is an enlarged view, partly in elevation and partly in cross section, of the yarn guide tube shown in Figure 2.

Figure 5 is a View partly in elevation and partly in cross section of another yarn guide tube.

Figure 6 is an elevational view of still another yarn guide tube.

Figure '7 is a perspective view of a complete yarn carrier of the type shown in Figure 1.

Figure 8 is a diagrammatic view of welding equipment, which maybe used in practicing the Welding method of the present invention for producing the yarn guides of Figures 1 to 7.

Figur 9 is a diagrammatic View to show the relative arrangement of tubular guide elements in the chucks of the welding equipment illustrated in Figure 8.

Figure 10 is a view similar to Figure 9 and illustrates the method for welding the tip of the guide tube shown for example in Figure 2.

The yarn carrier of Figures 1 and 7 comprises a yarn carrier member or supporting arm A, and a yarn guide tube 13. The yarn guide tube 13 is formed from three tubular elements 10, I2, and i2 and has substantially uniform internal and external diameters throughout. The tubular element H is preferably of flexible construction and may be formed of both round and flat wire in the same manner as the tube shown in Figure V of the Weisbecker Patent No. 2,101,801. A metallic ribbon or flat wire of stainless steel having a thickness of about 0.008 inch and a width of about 0.030 inch may be coiled to form the fiat wire spring in the tubular member I l The round Wire spring of the tubular member it may be formed of round wire stainless steel stock having a cross-sectional diameter of about 0.008 inch. The internal diameter of the yarn guide tube B is preferably on the order of 0.030 inch, and the external or outer diameter on the order of 0.046 inch.

The tubular element E2 is the tip of the guide tube 3 and may be formed of any suitable tubular stock having a continuous annular Wall over its entire length. Ihe tubular element i2 is preferably inflexible and of wear resisting character and may be formed of chromium, Carboloy, chromium alloys, or high carbon steel.

The tubular element 50 is preferably formed of stainless steel tubular stock and is externally threaded for screw threaded engagement with the yarn carrier member A, so that the Yarn guide tube B may be readily detached therefrom, as well as readily inserted therein.

The tubular elements 10, II and i2 are united by the welding method of this invention. To prepare the tubular elements for the welding operation, their ends to be welded are preferably ground perfectly flat. This treatment of the tubular elements will minimize the possibility of a bur being formed at the joint in the welding operation. Such welding may be accomplished by apparatus as illustrated diagrammatically in Figure 8. This welding apparatus may include a source 13 of alternating current, a transformer I4, and a rectiher for supplying energy to a condenser it. In the circuit between the rectifier i 5 and one terminal of the condenser 16, there is preferably provided two ballast resistance lamps ll, an adjustable load resistance 18, and a switch id. The switch 13 includes a manually operated switch arm for selective engagement with either of two contacts and 2|. When the switch arm is in engagement with the switch contact 20, the condenser HE is supplied with energy from the source of power l3 through the rectifier R5, the ballast resistance lamps ii, and the adjustable resistance I8. Movement of the switch arm out of engagement with the switch contact 20, opens the circuit between the condenser 50 and the source of power l3.

The welding apparatus also includes two relatively movable chucks, or vises, 22 and 23, which constitute welding terminals. The chuck 23 may be anchored in place, and the chuck 22 may be supported to fall by gravity action in a vertical direction toward the stationary chuck 23. The chuck 22 is electrically connected to one side of the condenser 5. The other chuck 23 is electrically connected to the switch contact 2|, so that when the latter is engaged by the arm of switch IS, the chuck 23 is electrically connected through the switch 20 and the resistance l3 to one terminal of the condenser i5. When the switch arm is moved away from contact 2!, the circuit to the welding terminals is open, and an attendant may safely clamp two of the yarn guide tubular elements, for xample H and $2, in the chucks, and otherwise make the necessary preparations for producing a welded joint.

The welding apparatus is also provided with a latch for releasably holding the chuck 22 in a raised position. Suitable electrical or mechanical control means of conventional form (not shown) interconnect the arm of the switch l9 and the latch 25, so that the latter will be automatically tripped to release the chuck 22 at the instant the switch arm is thrown into engagement with the contact 2i. The condenser it will, therefore, be included in the circuit of the chucks 22 and 23, as the chuck 22 falls to effect the percussion welding of the tubular ole- -ents l! and I2.

The method of welding may be as follows: The tubular guide members H and I2 are secured in the chucks 23 and 22 respectively, so as to project slightly therefrom and toward each other (see Figure 9), but with the chucks 23 and 22 in separated relation (see Figure 8).

The tubular elements H and (2 are preferably gripped closely adjacent their ends to be welded (see Figure 9) in order to confine substantially the welding to the end edges thereof. The arm of switch it is now in engagement with contact 20 to permit charging of the condenser The chucks 22 and 23 are then brought together so as to provide percussive en agement between the ends of the tubular members I l and I2 (see Figure 9). This operation is secured by throwing the arm of switch 19 into engagement with contact 2!, whereby the latch 25 is actuated to release the chuck 22 and, at the same instant, the condenser is is connected to the chuck 23. As the tubular elements it and 22 are brought into contact, the welding circuit is completed and the condenser l0 discharges through the current limiting resistance i8 to release the proper amount of welding heat at the joint being welded. The energy thus concentrated at the point of contact between the elements H and I2 is sufficiently great to produce a substantially perfect weld.

In the electric welding of coil spring tubes, it has been found that desirable results are accomplished if the winding of the coil forming the tube ll bears a certain relationship to the direction or" current flow in the tube. For example, with the method and apparatus illustrated by Figures 8 and 9, the coil spring tubular element ll is preferably of the right hand wound type, and the current flows in the tubular element H towards its end to be welded. The chuck 23 also preferably grips the coil spring tubular element ii at a listance from the end to be welded of about one convolution. The welding current will then flow circumferentially about the end of the tubular element H and provide a magnetic field about the axis of the wire which extends between the chuck 23 and the end edge of the tubular element II. This magnetic field will have such direction that it will tend to drive particles which may possibly be spattered in the welding operation, away from the interior of the tubular element H, across its and edge and toward the outside of the tubular element II. The lines of magnetic force extend upwardly (looking at Figure 9) and axially within the tubular element II and then outwardly over its end being welded. The magnetic field set up by the current flow in the coil spring tubular element H, therefore, assists in providing a flush joint at the interior of the welded tub and in preventing the deposit of particles within the welded tube which would either clog the same or have an abrasive action on yarn passing therethrough.

It is my discovery that the foregoing procedure will integrally unite the tubular elements I l and l2 with a strong bond and generally without any external or internal welding bur or extruded metal at or adjacent the welded joint. This invention, therefore, avoids flow of metal to the interior of the yarn guide tube during the welding operation and accomplishes a most important result.

Any substantial amount of extruded metal in the guide tube B will either render the latter useless or require a relatively expensive and time consuming operation for its removal. The presence of metal within a yarn guide tube as a result of its being welded will, if not removed, be apt to damage or cut yarn when the yarn guide tube is being used in the yarn laying operations of a knitting machine. Heretofore, the knitting art has found it difficult to weld yarn guide tubes, because of the metal usually extruded at the welded joint. Furthermore, the welding of yarn guide tubes for knitting machines has, heretofore, been thought impractical because of the very small size of stock which is used in forming the guide tubes. The method of this invention, however, may be successfully followed in making relatively small knitting machine yarn guide tubes having a wall thickness on the order of 0.008 inch and an internal diameter on the order of 0.030 inch.

A preferred machine for the welding of the present guide tubes is one in which the chucks 22 and 23 are arranged for relative movement in a vertical direction. The chuck 22, for example, may be positioned above the chuck 23 and slidably mounted in a vertical guide 24 of the welding machine so that it (chuck 22) may be raised a certain distance, secured in the raised position by the latch 25, and released at the will of an attendant to fall by gravity action. The chucks 22 and 23 should be so relatively arranged that the chuck 22 in its descent will bring its tubular element (for example l2) into exact alignment with the tubular element (for example ll) supported by the chuck 23. The mass of the gravity propelled chuck 22 is preferably such as to produce a static force of 10 pounds at the instant of welding. The drop or fall of the chuck 22 is preferably such that its velocity is on the order of 0.002 inch per 0.00001 second, or 200 inches per second, at the instant the tubular elements are brought into contact. This ratio of mass and velocity, when small tubular elements having flat surfaces are being welded, will insure a substantially perfect weld and yet substantially avoid the possibility of metal being forced out of the joint and into the interior of the guide tube.

The source of power l3 and the transformer l4 are preferably so related as to deliver a transformer output of about 0.5 ampere at 500 volts. The joint at the instant of welding will then be subjected to'a current of about 10 to 15 thousand amperes at about 590 volts. To produce this con denser discharge current, the condenser it may be of the paper dielectric type having a capacity of about 800 microfarads or its equivalent. A condenser of different capacity is preferable if the parts to be welded are of different size in crosssection from that described herein. The value of the condenser (in microfarads) is preferably varied in proportion to the variation of the area of the surfaces to be welded.

The condenser Iii effects its discharge in such a brief period of time that the welding operation is completed within a very small fraction of one second-on the order of 0.00001 of a second. This fraction of a second measures the duration of the welding heat at the point being welded. This welding interval is of such short duration that heating of the tubular elements H and I2, except in the area closely adjacent the Welded joint, is substantially avoided. Any free oscillating current which may be present after the welding is completed, is dampened out by the resistance 8. The welding operation, therefore, does not impair the resilient property of the tubular element H or the Wear resisting character of the tubular element E2. The interval of time during which the current continues to flow through the joint being welded is in ac cordance with the resistance of the welding circuit. An adjustable resistance as shown at E8 in Figure 8 is, therefore, preferably included in the Welding circuit, in order that an attendant may vary the resistance and thereby control the duration of the Welding operation,

Conventional practice may be followed to reduce inductance of the wiring of the welding equipment to a minimum and thereby avoid free oscillating currents which would tend to burn the parts being welded.

Ihe tubular elements id and ii may be and preferably are united in the same manner as described with respect to the Welding of the tubular elements H and Hi. The tubular element IE! is preferably provided with its external screw thread prior to its being joined to the tubular element H.

The guide tube B, after its elements it], i i and i2 are welded together, may be machined or otherwise treated to grind away, cut or remove any metallic particles which may have been formed on the guide tube interior walls during the welding operation. This step obviously is not required where the welding operation leaves a clean joint and provides a guide tube with a uniform bore free of obstructions or metallic particles that might cut or catch yarn passing through the guide tube. Usually, the welding operation results in such a clean joint that the interior of the guide tube does not require a cleaning operation to prepare the tube for feeding yarn. in the event, the guide tube joints require cleaning to remove extruded metal, the latter is so small in quantity that the cleaning operation can be readily performed in a relatively simple operation and much more quickly than would be the case if the tube were Welded according to the methods heretofore known in the knitting art. The interior of the tubes welded according to this invention may be cleaned, when necessary, by means of an abrasive-coated wire or cord, such as emery coated cord, which is passed back and forth through the tube.

Another form of guide tube which may be formed according to this invention is shown at C in Figure 2. This guide tube 0 comprises tubular elements 3i: and 3!. The tubular element 3% is similar to the tubular element is of Figures 1 and 3 and may be welded to the tubular element 25 in the same manner as described with respect to the tubular elements it, II and S2.

The tubular element St, like the tubular element I I described above, is formed of both round and fiat wire. The round wire, however, does not extend into the tip end 32 of the tubular element 3!. The tip 32 of the tubular element (if is, therefore, formed solely by one or more (preferably a few) convolutions of the fiat wire as shown clearly in Figure 4. These few convolutions of flat wire in the tip 32 may be welded together in abutting relation (see Figure 4) in substantially the same manner as the tubular elements l I and [2. In the event the tube 3! is madefrom stock such as the tubular element ii of Figure l, the round wire in the tip 532 is removed prior to welding of the latter.

The tubular element SI, for example, may be gripped by the chuck 23 as diagrammatically indicated in Figure 10, and an electrode 33 may be carried by the chuck 22. With this arrangement, the apparatus illustrated in Figure 8 will operate as above described and effect welding when the electrode 33 strike the end of tip In preparing the tubular element 3! for the welding operation, the convolutions in the tip 32 may be slightly spaced apart. The force of the falling electrode 33 will press the convolutions of the tip 32 into contacting engagement as the welding current is passed therethrough. The convolutions in the tip 32, if desired, may first be formed in abutting relation and then welded together in the manner already described. It will be noted (see Figure 10) that the chuck 23 grips the tube 3| at the inner end of tip ihis will confine the welding operation to the tip 32.

Figure 5 of the drawings shows a guide tube D comprising a flexible tubular element ii; and a tubular tip 4! which are similar to the tubular elements if and I2 respectively of Figures 1, 3, 7 and 9. The tubular elements and 4! are preferably welded together in the same manner as described with respect to the tubular elements f l and I2.

The yarn guide tube E of Figure 6 is constructed the same as the tubular member 3! of Figures 2, 4 and 10, and has a tubular tip 5| formed in the same manner a the tip 32.

The yarn guide tubes D and E may be secured in a yarn carrier in any suitable manner. The

guide tubes D and E preferably are frictionally mounted in a yarn carrier as disclosed, for example, in the application of Frank G. Weisbecker Serial No. 218,448 (now Patent No. 2,214,712, dated September 10, 1940) or in my copending application Serial No. 263,738 (now Patent No. 2,218,978, dated October 22, 1940).

After the yarn guide tubes B and D are constructed as described above, they preferably have their tips (|2 and 4|) subjected to a hardening process. This proces is preferably performed by treating each yarn guide individually. A preferred process is to heat treat each tip ([2 and 4|) by electric resistance heating to raise its temperature rapidly. The complete guide tube (B or D), or its heated tip (l2 or 4|) is then immersed instantly in cold water or other cooling medium. The tips (l2 and 4|) are heated and cooled rapidly so as not to destroy the resilient properties of the spring portions of the yarn guide tubes B and D. As a result of the guide tubes B and D being first welded, then having their tips heat treated, and finally secured in yarn carriers by a mechanical joint and without the use of heat, the completed yarn carriers when ready for installation in knitting machines will have guide tips which are characterized by their great hardness and coiled wire portions which are characterized by their flexibility. Experience shows that guide tubes hav- 1 ing their tips hardened after the welding thereof are superior to guides having their tips hardened by heat treatment prior to welding The described method for making yarn carriers avoids the guide tips being subjected to drawing temperatures, such as would be the case, if the yarn guide tubes B, C, D and E were soft soldered to the yarn carrier members (for example A), or if the tips l2 and 4| were secured to the flexible tubular members H and respectively by soft soldering. The tips 32 and 5| are also not subjected to drawing temperatures, since they are formed by welding as described above.

The described method of making yarn carriers results in providing longer life for the guide tubes in actual use, a well as highly satisfactory guide tubes.

The foregoing is illustrative, and it will be understood that this invention includes all embodiments and modifications coming within the scope of the appended claims.

I claim:

1. The method of forming knitting machine yarn carrier guide tubes having relatively thin walls, which method comprises providing tubular stock of coiled wire, effecting percussive engagement between the edge of certain adjacent convolutions in said tubular stock, and producing an intensive electric welding heat at said edges during said percussive engagement, said welding heat being of relatively short duration and being confined substantially to said edges.

2. The method of forming a knitting machine yarn carrier guide tube, which comprises forming a resilient tubular member of coiled metal of the right hand wound type, forming a substantially inflexible tubular tip with internal and external diameters of substantially the same dimensions as one end of said tubular member, eifecting percussive engagement between the edge of said end of said member and an end edge of said tip, and producing an intensive electric welding heat at said end edges during said percussive engagement, said welding h'eat being of relatively short duration and being confined substantially to said end edges and being formed by a welding current flowing through at least one convolution of said resilient member and from said convolution to said tubular tip.

3. In a method of making a yarn guide tube for knitting machines, the steps comprising providing a tip element and a helically coiled spring tube of the right hand wound type, effecting percussive engagement between aid tip element and an end edge of said coiled spring tube, and passing a weldin current between said end edge and said tip element simultaneously with said percussive engagement, the direction of flow of said current being from said coiled spring tube to said tip element and passing through at least one convolution of said coiled wire.

4. In a method of making a yarn guide tube for knitting machines, the steps comprising providing a coiled spring tubular element of the right hand wound type and a solid wall tubular element of relatively rigid construction, the internal and external diameters of one end of said coiled spring element being substantially the same as the internal and external diameters of one end of aid relatively rigid element, effecting percussive engagement of said element ends in edge to edge relation, and passing a welding current between said edges simultaneously with said percussive engagement, the direction of flow of said current being from said coiled element to said relatively rigid element and passing through at least one convolution of said coiled wire.

5. A method for making a yarn guide tube wherein an end portion thereof is of solid wall construction and relatively inflexible and an intermediate tube portion is of resilient construction formed of helicaliy coiled wire of the right hand wound type, wherein said end portion and said intermediate portion have the same in ternal diameter and the same external diameter, and wherein said end portion is secured in edge to edge relation to a convolution forming a continuation of said coiled wire, said method com prising effecting percussive engagement of said edges with a force on the order of ten pounds; and simultaneously passing a welding current on the order of ten thousand to fifteen thousand amperes at a voltage on the order of five hundred volts through said convolution and from said convolution through said edges to said end portion, the duration of the welding current being on the order of 0.00001 of one second.

6. A method for making a yarn guide tube wherein an end portion thereof i a tubular element and an intermediate portion is of resilient construction formed of helically coiled wire of the ri ht hand wound type, and wherein said end portion and said intermediate portion have substantially the same internal diameter and substantially the same external diameter, the method comprising providing an end of said element and an end of said coiled wire portion with flat edges, effecting percussive engagement of said edges with a force on the order of ten pounds, and passing a welding current on the order of ten thousand to fifteen thousand amperes at a voltage on the order of five hundred volts between said edges at the time of said percussive engagement, the duration of the flow of said current being on the order of 0.00001 of one second, and the direction of the current flow being from said coiled wire portion to said element.

AUGUST L. WEISBECKER. 

